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Collicular Arteries
The collicular artery or ''quadrigeminal artery'' arises from the posterior cerebral artery. This small artery supplies portions of the midbrain, especially the superior colliculus, inferior colliculus, and tectum. Structure The collicular artery originates from P1 segment of the posterior cerebral artery near the side of interpeduncular fossa. It arises just distal to the bifurcation of the basilar artery. It runs posteriorly along the cerebral peduncle passing the crural and ambient cisterns. It then gives off branches to supply quadrigeminal plate and the adjacent structures in the midbrain. The origin of this artery is proximal to the origin of medial and lateral posterior choroidal branch of the posterior cerebral artery. The main collicular artery also gives branch to an accessory collicular artery. Branches ;Anterior branches Anteromedial branches are rare but sometimes observed to contribute as part of the interpeduncular fossa's lateral rami of the intermediate pedicle. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cerebral Artery
The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, part of the back of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifurcates into the left and right posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries. Structure The posterior cerebral artery is subdivided into 4 sections P1: pre-communicating segment * Originated at the termination of the basilar artery * May give rise to the artery of Percheron if present P2: post-communicating segment * From the PCOM around the midbrain * Terminates as it enters the quadrigeminal ganglion * Gives rise to the choroidal branches (medial and lateral posterior choroidal arteries) P3: quadrigeminal segment * Courses posteromedially through the quadrigeminal cistern * Terminates as it enters the sulk of the occipital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basilar Artery
The basilar artery () is one of the arteries that supplies the brain with oxygen-rich blood. The two vertebral arteries and the basilar artery are known as the vertebral basilar system, which supplies blood to the posterior part of the circle of Willis and joins with blood supplied to the anterior part of the circle of Willis from the internal carotid arteries. Structure The basilar artery arises from the union of the two vertebral arteries at the junction between the medulla oblongata and the pons between the abducens nerves (CN VI). The diameter of the basilar artery range from 1.5 to 6.6 mm. It ascends superiorly in the basilar sulcus of the ventral pons and divides at the junction of the midbrain and pons into the posterior cerebral arteries. Its branches from caudal to rostral include: *anterior inferior cerebellar artery *labyrinthine artery (<15% of people, usually branches from the anterior inferior cerebellar artery) * |
Superior Colliculus
In neuroanatomy, the superior colliculus () is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form ''tectal'' is commonly used for both structures. In mammals, the superior colliculus forms a major component of the midbrain. It is a paired structure and together with the paired inferior colliculi forms the corpora quadrigemina. The superior colliculus is a layered structure, with a pattern that is similar to all mammals. The layers can be grouped into the superficial layers ( stratum opticum and above) and the deeper remaining layers. Neurons in the superficial layers receive direct input from the retina and respond almost exclusively to visual stimuli. Many neurons in the deeper layers also respond to other modalities, and some respond to stimuli in multiple modalities. The deeper layers also contain a population of motor-related neurons, capable of activat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Colliculus
The inferior colliculus (IC) (Latin for ''lower hill'') is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex. The inferior colliculus has three subdivisions: the central nucleus, a dorsal cortex by which it is surrounded, and an external cortex which is located laterally. Its bimodal neurons are implicated in auditory-somatosensory interaction, receiving projections from somatosensory nuclei. This multisensory integration may underlie a filtering of self-effected sounds from vocalization, chewing, or respiration activities. The inferior colliculi together with the superior colliculi form the eminences of the corpora quadrigemina, and also part of the tectal region of the midbrain. The inferior colliculus lies caudal to its counterpart – the superior colliculus – above the trochlear nerve, and at the base of the projection of the medial genicu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midbrain
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', "middle", and ''enkephalos'', "brain". Structure The principal regions of the midbrain are the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles. Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while caudally it adjoins the hindbrain (pons, medulla and cerebellum). In the rostral direction, the midbrain noticeably splays laterally. Sectioning of the midbrain is usually performed axially, at one of two levels – that of the superior colliculi, or that of the inferior colliculi. One common technique for remembering the structures of the midbrain involves visualizing these cross-sections (especially at the level of the superior colliculi) as the upside-down face of a be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Colliculus
In neuroanatomy, the superior colliculus () is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form ''tectal'' is commonly used for both structures. In mammals, the superior colliculus forms a major component of the midbrain. It is a paired structure and together with the paired inferior colliculi forms the corpora quadrigemina. The superior colliculus is a layered structure, with a pattern that is similar to all mammals. The layers can be grouped into the superficial layers ( stratum opticum and above) and the deeper remaining layers. Neurons in the superficial layers receive direct input from the retina and respond almost exclusively to visual stimuli. Many neurons in the deeper layers also respond to other modalities, and some respond to stimuli in multiple modalities. The deeper layers also contain a population of motor-related neurons, capable of activat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Colliculus
The inferior colliculus (IC) (Latin for ''lower hill'') is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex. The inferior colliculus has three subdivisions: the central nucleus, a dorsal cortex by which it is surrounded, and an external cortex which is located laterally. Its bimodal neurons are implicated in auditory-somatosensory interaction, receiving projections from somatosensory nuclei. This multisensory integration may underlie a filtering of self-effected sounds from vocalization, chewing, or respiration activities. The inferior colliculi together with the superior colliculi form the eminences of the corpora quadrigemina, and also part of the tectal region of the midbrain. The inferior colliculus lies caudal to its counterpart – the superior colliculus – above the trochlear nerve, and at the base of the projection of the medial genicu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectum
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', "middle", and ''enkephalos'', "brain". Structure The principal regions of the midbrain are the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles. Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while caudally it adjoins the hindbrain (pons, medulla and cerebellum). In the rostral direction, the midbrain noticeably splays laterally. Sectioning of the midbrain is usually performed axially, at one of two levels – that of the superior colliculi, or that of the inferior colliculi. One common technique for remembering the structures of the midbrain involves visualizing these cross-sections (especially at the level of the superior colliculi) as the upside-down face of a bear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpeduncular Fossa
The interpeduncular fossa is a deep depression of the ventral surface of the midbrain between the two crura cerebri. It has been found in humans and macaques, but not in rats or mice, showing that this is a relatively new evolutionary region. Anatomy The interpeduncular fossa is a somewhat rhomboid-shaped area of the base of the brain. Features The lateral wall of the interpeduncular fossa bears a groove - the oculomotor sulcus - from which rootlets of the oculomotor nerve emerge from the substance of the brainstem and aggregate into a single fascicle. Anatomical relations The ventral tegmental area lies at the depth of the interpeduncular fossa. Boundaries The interpeduncular fossa is in front by the optic chiasma, behind by the antero-superior surface of the pons, antero-laterally by the converging optic tracts, and postero-laterally by the diverging cerebral peduncles. The floor of interpeduncular fossa, from behind forward, are the posterior perforated substance, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambient Cistern
The ambient cistern is a bilaterally paired (one on each side of the body) subarachnoid cistern situated at either lateral aspect of the mesencephalon (midbrain). Each ambient cistern has a supratentorial compartment and an infratentorial compartment. Each is continuous anteriorly with the interpeduncular cistern, and posteriorly with the quadrigeminal cistern. Anatomy Each ambient cistern is situated between (the parahippocampal gyrus and dentate gyrus of) the temporal lobe (laterally), and the lateral aspect of the posterior of the mesencephalon posterior to the cerebral peduncle (medially). Relations Each ambient cistern extends anterolaterally around the mesencephalon to become continuous rostrally/anteriorly with the interpeduncular cistern. Each ambient cistern is continuous dorsally/posteriorly with the quadrigeminal cistern; inversely, each ambient cistern is an anterolateral extension of the quadrigeminal cistern on either side (some sources define the quad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrigeminal Plate
The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal (alertness), and temperature regulation. The name comes from the Greek ''mesos'', "middle", and ''enkephalos'', "brain". Structure The principal regions of the midbrain are the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles. wikt:rostral, Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while wikt:caudal, caudally it adjoins the hindbrain (pons, Medulla oblongata, medulla and cerebellum). In the rostral direction, the midbrain noticeably splays laterally. Sectioning of the midbrain is usually performed axially, at one of two levels – that of the superior colliculi, or that of the inferior colliculi. One common technique for remembering the structures of the midbrain involves visualizing these cross-sections (especially at the level of the superior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
